Gravity-assisted drain valve for restricting intake of mildew spores

ABSTRACT

A drain valve that prevents entry of odious airborne particulates into the habited environment while allowing for drainage of wastewater. The improvements include a disc with leaves cantilevered from a perimeter lip allowing the valve to operate in a drain with limited clearance between the opening and the drain crosshair below, a structural brace that effectively seals the center of the drain while allowing for through-passage of the drain strainer bolt, a gap at the perimeter edge of each leaf to prevent interference with an opposing edge, and rounded leaf edges and rounded vertices to prevent snagging of hair follicles and other draining matter. Also disclosed is a combined drain strainer and drain valve, and a drain valve installable within a drain pipe beneath the drain opening.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is entitled to the benefit of Provisional Patent Application Ser. No. 61/171,561, Gravity-assisted drain valve for restricting intake of mildew spores, filed Apr. 22, 2009, incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention has generally to do with drain valves, and more particularly a valve that limits the entry of unhealthy airborne particulates into the habited environment.

2. Description of Related Art

A conventional backflow prevention devices such as a backwater valves is a standard component of drainage and water storage systems to restrict the backflow of sewage water, rainwater or seawater of negative pressure from a rising water table, thus protecting the habited environment from damage, unhealthy exposure or contamination. Backflow prevention valves are installed within the plumbing pipeline, between the main supply line and the private service line. Access to a test cock provides means of performance testing. Repair or replacement typically requires the attention of qualified service personnel.

A backflow prevention device does not protect the habited environment from exposure to contaminated water or unhealthy airborne particulates existing in the pipes between it and the drain opening.

A conventional drain trap protects the habited environment from exposure to unhealthy airborne particulates and gases within the plumbing system. The drain trap is a u-shaped section of pipe in which a volume of standing water isolates the atmosphere within the pipes from the atmosphere exposed to the habited environment. The drain trap is typically situated within close proximity of the drain opening in a sink, or after the drain shoe in household shower and bathtubs. The drain trap does not protect the habited environment from contaminated air existing in the area between it, the drain shoe and drain opening.

Bathtub stoppers completely block the drain from entry of odious particles. Drain stoppers are disadvantaged because they must be manually removed to allow for drainage of graywater.

Semi-porous drain strainers are commonly employed to catch debris before it enters the drain system. While a drain strainer may alter airflow within the drain and thereby limit entry of odious particulates, the holes in a drain strainer prevent the device from substantially preventing or eliminating the entry of particulates.

A conventional disposal drain shield installed with household sink electric disposal units is a flexible device with members such as channels or flaps that open with pressure exerted by the gravity of draining water. The primary purpose of such a shield is to block objects struck by chopping blades in the drain from being projected out of the drain, while flexing to allow for the downflow of wastewater and disposable material. Such a device is installed as a component part of the disposal unit, drain and drain shoe and is typically expected to survive for the life of the disposal unit. Constructed of a material (i.e. rubber) that is capable of managing the forces exerted on its lower surface by projectiles within the disposal system, a disposal drain shield is poorly equipped to provide significant prevention or elimination of the passage of airborne particulates because of openings that exist at the center of the drain and between channels. Further, because disposal drain shields are not typically employed in bathtubs, no solution for interfacing with a drain strainer bolt is provided. Because disposal drain shields must allow for the rapid drainage of liquids and solid waste, the drain shield typically has a ½″ to 1″ opening at the center of the drain when in its closed position.

U.S. Patent 2009050546 describes a drain trap that prevents the entry of noxious odors. The drain trap has a tubular shape with a storage space requiring substantial clearance beneath the drain opening for operation.

Chinese Patent CN 201183977 (Y) describes an insect-proof floor drain. The drain has a hinged door which requires significant clearance beneath the drain opening and is incapable of operating in a drain having a drain strainer bolt passing through the center of the drain.

Japan Patent JP2002339427 (A) describes a valve trap that isolates the habited environment from exposure to gases, odors and vermin. The drain valve has a hinged door which requires significant clearance beneath the drain opening and is incapable of operating in a drain having a drain strainer bolt passing through the center of the drain.

BRIEF SUMMARY OF THE INVENTION

The object of the invention is achieved by a flexible, planar disc with a lip at its perimeter that sits above the exterior lip of a conventional drain opening and below a conventional drain strainer, having a leaf cantilevered from the lip such that the weight of water droplets on its surface causes the leaf to collapse into an open position, allowing drain water to flow.

In another aspect of the invention, the disc may include a coplanar crosshair brace with a central brace hole allowing for the through-passage of a conventional drain strainer bolt for its connection to a conventional drain crosshair in the drain; and providing structural support to the disc; and being coplanar with the lip and leaves of the disc, retaining the low-profile of the disc; and by interface with the drain strainer bolt, maintaining the leaves at exact center over the drain opening without interfering with the operation of the leaves or drain strainer bolt; and with its central brace hole conforming to the diameter of the drain strainer bolt, minimizing opportunity for the entry of odious airborne particulates into the household.

In one embodiment of the invention, the collapsing portion of the leaf is separated from opposing surfaces by a single slit, thereby distanced from opposing edge by the width of the slit.

In one embodiment of the invention, the collapsing portion of the leaf is separated from opposing surfaces by a narrow gap, thereby distanced from opposing edge by the width of the gap, where the gap is of minimal width to allow the leaf to function free of entanglement or interaction with the opposing edge while continuing to perform its primary function in substantially limiting intake of airborne particulates when the leaf is in a closed position.

In another aspect of the invention, the endpoints and vertices of the gap between the leaves and opposing edges are rounded to eliminate sharp corners in order to facilitate the successful drainage of hair follicles and other particles and to provide a self-cleaning function of each leaf as it sweeps past the opposing edge.

In another aspect of the invention, the disc, leaves and brace are of a unified construction.

In another aspect of the invention, the disc has a reinforced lip which enables it to be installed above and outside the drain opening while providing support to its leaf members.

In another aspect of the invention, the disc has one or more dual-purpose leaves which serve both as leaves in the function of the valve to protect the habited environment form exposure, and also as tabs which can be bent or removed to allow for the installation of the valve under a snap-in drain strainer.

In another embodiment of the invention, the disc exists at the floor of cup inserted into a conventional drain opening with the cup having a lip seated securely on the drain opening lip, so that the disc exists below the floor of the tub, rather than substantially flush with the surface of the drain opening, and so the cup collects a small volume of drainwater above the leaves and thereby acts as a trap to further limit the entry of unhealthy particulates or gases.

In another aspect of the invention, the disc is combined with a bathtub drain strainer cap, having a unified surface shared between the disc at its perimeter lip and the drain strainer's underside perimeter.

In another aspect of the invention, the disc is unified as the lid of in-drain strainer basket, with the disc and a strainer basket sharing a unified lip that sits flush with the lip of a conventional drain opening, with the disc's leaves cantilevered over the strainer basket and the strainer basket existing within the drain opening, and the entire unit capable of sitting below a conventional drain strainer cap.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 shows an example valve of this invention;

FIG. 2 shows the typical installation of an example valve of this invention beneath a conventional drain strainer and above the drain opening.

FIG. 3 shows two views of an example valve in its open position with water droplets causing the valve leaves to collapse;

FIG. 4 shows a magnified view of the leaf perimeter gap at the perimeter edge of a leaf;

FIG. 5 shows an example combined drain strainer and drain valve;

FIG. 6 shows an example drain valve cup;

DETAILED DESCRIPTION OF THE INVENTION

The need arises for a drain valve that limits the intake of odious particulates such as mildew spores into the habited environment while allowing for the normal drainage of fluids such as bathtub drainwater. The need further arises for such a valve that is easy to manufacture, disposable and easily replaced as a do-it-yourself project by an untrained homeowner with no plumbing experience and minimal tools. The need arises for such an intake restrictor valve to be substantially flat so as to fit beneath a conventional shower/bath drain strainer, to have a method for opening and closing that does not interfere with the drain shoe walls, the drain crosshair, the drain strainer and the centered drain strainer bolt.

The valve of FIG. 1 is a substantially flat disc and has a Perimeter Lip that is substantially circular and encompasses the valve. The valve has two Drain Leaves 101 and 109. Brace 105 exists across the perimeter, with Brace Hole 107 at its center. Gap 106 exists between the edge of leaf 109 and opposing edges on the Perimeter Lip and Brace, and this gap is hereafter referred to as the Leaf Perimeter Gap. The Leaf Perimeter Gap has Endpoints 104 and 110 and Vertex 102 between endpoints. Each leaf is cantilevered at an area 103 that exists between the Perimeter Lip and the central portion of the leaf.

The valve of FIG. 1 lies flat on the floor of a bathtub or shower tub, disposed with respect to downward gravitational forces so that the exterior, upward-facing surface of its leaves are subject to the weight of water droplets on their surface, thereby allowing the leaves to collapse and allow the release of the droplets into the drain. The valve of FIG. 1 is typically installed as shown at 200 in FIG. 2, beneath a conventional drain strainer 210 and above drain 220. Drain strainer 210, drain 220 and bolt 230 are shown as examples, not part of the valve of this invention.

Fully assembled, drain strainer bolt 230 passes through drain strainer 210 and valve 200 into a centered threaded opening in crosshair 221 of drain 220. As the bolt is tightened, Perimeter Lip 205 is mated to upper surface 222 of drain 220. Bolt 204 passes through a center hole in drain strainer 210 and through Center Hole 206 in valve Brace 204, keeping the valve centered over the drain opening in drain 220.

When Leaves 202 and 203 of the valve of FIG. 2 are in their closed position as shown, airborne particulates, notable spores of mildew and other molds and fungi, are limited in entry into the habited environment. Rather than being exposed in large concentrations into the habited environment, the airborne contaminants are restricted to an area within the drain shoe and up to the trap. A fraction of these contaminants may be captured on the pipe walls before being flushed through the system. Another fraction may be aerated in contact with rushing drain water and subsequently flushed through the system. A more significant portion may be flushed in bubbles or air pockets pushed forward by a volume of exiting drain water. The combined effect is to a) prevent the exposure of the habited environment to the entire set of contaminants; b) allow for the capture and flushing of a portion of the airborne contaminants; and c) allow for the successful fumigation of the pipes when the valve is used in conjunction with a disinfectant.

The Perimeter Lip 108 of FIG. 1 sits above and outside an ordinary shower or bathtub drain opening, centered in alignment with the exterior lip of the drain. The Perimeter Lip may be constructed of a rigid material or of the same material as the leaves, with a flexing soft edge at 103 and 111 that provide just enough support to allow the leaves to remain flat as they are cantilevered inward and over the drain opening.

Leaves 101 and 109 may be constructed of a semi-rigid material such as plastic of 5 mil thickness, which allows them to be cantilevered over the drain opening; to flex downward under the weight of water droplets on their exterior surface; and to return from a collapsed position to a substantially flat (closed) position after water has fallen into the drain. It is anticipated that Leaves 101 and 109 may be constructed of a rigid material and combined with a mechanical spring at the end of the leaf near the lip that allows the leaves to dip into the drain and return to a closed position.

Brace 105 provides support to offload forces acting on the perimeter lip as the leaves are pressed downward by draining water. An ordinary drain bolt, for example of the type shown at 230 in FIG. 2, passes through Center Hole 107 in FIG. 1. Thus, Brace 105 works in combination with Center Hole 107 to provide a means to maintain a centered orientation of the leaves over the drain opening, thus allowing the leaves to be shaped at precise tolerances with respect to the drain opening to maximize drainage and performance.

Leaf Perimeter Gap 106, which measures approximately ½ mm from leaf edge to its opposing edge, allows the leaves to dip and return to closed position without interaction with the lip; and allows the leaves to function without entanglement with spurs of plastic or other artifacts produced on the lip edge during construction of the valve; and allows the leaves to function without entanglement with hair follicles or soap scum that collect on the lip edge.

The Leaf Perimeter Gap also advantages the valve by allowing for the release of small volumes of drain water, hair follicles and small particles of waste mater in the drain water even when the Leaf Perimeter Gap is in its closed position. The Leaf Perimeter Gap further advantages the valve by allowing for a modicum of evaporation and circulation of air within the drain and the maintenance of equal air pressure between exterior and interior environments. The total area of the Leaf Perimeter Gap on the valve is a small fraction of the leaf area, thus ensuring that major concentrations of mildew spores are suitably contained within the drain shoe.

The shape of Leaf 109 and the disposition of the flexing surface area at 103 allow the leaves to collapse into the drain while avoiding contact with a center drain strainer bolt that passes through Brace Hole 105. The distance between endpoints 104 and 110 that defines the flexing surface at 103 is critical in providing support to the leaves; providing adequate flexure of the leaves in a downward direction; and defines the direction of flex while preventing the leaf from interacting with the drain strainer bolt that passes through Brace Hole 105.

A view of the valve at 300 in FIG. 3 shows the valve in its open position, as it would respond to water droplets falling on the surface of leaves 301 and 302. Arrows show the downward direction of the collapse of each leaf, the flexure at areas 303 and 304 where the leaves are cantilevered from Perimeter Lip 305. An axonometric view of the same valve as shown at 310 in FIG. 3 provides an alternate perspective on how the leaves collapse downward under the weight of water droplets applying downward force upon them.

The valve at 400 in FIG. 4 is shown with two areas magnified, namely the Leaf Perimeter Gap vertex region 401 magnified at 410 and the Leaf Perimeter Gap endpoint 402 magnified at 420. These magnified views show the endpoints and vertices of the Leaf Perimeter Gap which, by virtue of being rounded, allow for the passage of hair and other particles that otherwise would be snagged on sharp endpoints and corners or wedged in acutely angled areas of the leaf edge. The rounded vertex at the distal end of the cantilevered leaf and its rounded opposing edge on the perimeter rim facilitates a self-cleaning function as the leaf sweeps past the opposing surface each time it is actuated.

Magnified views 410 and 420 further illustrate that the Leaf Perimeter Gap separates the edge of the leaf from its opposing edge, rather than sharing a narrow slit between the leaf and its opposing surface. The Leaf Perimeter Gap prevents interference between a leaf and its opposing surface caused by burrs left from die-cut manufacturing or by entanglement with buildup of particle matter and soapscum.

In another embodiment of the drain valve of this invention, the drain valves described by FIGS. 1, 2, 3 and 4 can be manufactured together with a drain strainer to produce a combined drain strainer and drain valve. An example of this embodiment is shown in FIG. 5. An axonometric view at 500 in FIG. 5 shows the upper surface of a combined drain strainer and drain valve, with drain valve shown in hidden lines attached to the underside rim of the drain strainer. The example drain strainer of FIG. 5 is similar to the type shown in FIG. 2 (where it was not part of the described invention). An axonometric view of the underside of this example combined drain strainer and drain valve is shown at 510 in FIG. 5. Here, it is shown that while the drain valve and drain strainer may be attached or unified at the perimeter rim, the leaves of the drain valve are freely capable of dropping into the drain opening when the drain strainer is secured above the drain.

The assembly at 520 in FIG. 5 shows the drain strainer bolt as it would pass through the combined drain strainer and drain valve into the drain opening, where the bolt would mate with the drain crosshair. The bolt, drain and drain crosshair are shown as examples and are not part of this combined drain strainer and drain valve of this embodiment.

In another embodiment of the drain valve of this invention, the valve sits at the floor of a cup which is itself installable within a drain opening. The cup seals the walls of the drain opening so that all drainwater runs into the cup and collects atop the drain valve. As described with FIGS. 1, 2, 3 and 4, the drain valve has leaves cantilevered so they collapse with the weight of water.

An example of this embodiment is shown in FIG. 6. The drain valve cup at 600 has a cylindrical shape with walls that match the inside diameter of a drainpipe and a floor that has leaves of the type described in FIGS. 1, 2, 3 and 4. Here, however, the perimeter rim of the drain valve does not sit over the drain opening exterior rim, it is sealingly attached to the lower portion of the cup walls to form the cup floor. The cup and floor fit within the drain opening as shown in the assembly drawing at 610. The advantage of the cup is that it is capable of collecting a small amount of water before the leaves collapse, thus improving the ability of the valve to seal the habited environment from the intake of airborne particulates.

It is anticipated that the valve of this invention may have any number of drain leaves, with varying shapes and responses to gravitational force of drain water acting downwardly upon them. It is also anticipated that drain leaves may themselves be slightly cupped or have other 3-dimensional shapes which enable them to capture and direct drain water flow while preventing backflow of airborne or waterborne contaminants.

It is anticipated that the valve of this invention may be combined with means for releasing a disinfectant, deodorizing agent, pesticide or fumigating chemical into the drain shoe.

It is anticipated that the valve of this invention may be combined with a bristled hair strainer below the drain opening and may exist at the bottom of a hair strainer.

Although the primary embodiment of this invention is a round disc, it is anticipated that the valve of this invention may have rectilinear shapes, with a leaf that is suited to discharge water into a rectilinear drain opening.

CONCLUSION

The foregoing Detailed description has disclosed to those skilled in the relevant disciplines how to make and use the drain valves of the invention and has also disclosed the best mode presently known to the inventor of making and using such drain valves. It will however be immediately apparent to those skilled in the relevant disciplines that drain valves made according to the principles of the invention may be implemented in many ways other than the ways disclosed herein. For example, the drain valve may be made of any present or future material that serves the cantilevered leaves in flexing and returning to a closed state. Further, the shape of the valve may take many forms, including non-planar forms. For all of the foregoing reasons, the Detailed Description is to be regarded as being in all respects exemplary and not restrictive, and the breadth of the invention disclosed herein is to be determined not from the Detailed Description, but rather from the claims as interpreted with the full breadth permitted by the patent laws. 

1. A drain valve installable on a wastewater drain having a vertical drain pipe and a drain opening with an adjacent drain rim, the drain valve comprising: a substantially flexible disc having a perimeter rim portion and a central portion; the perimeter rim portion having top and bottom surfaces and being adapted to substantially sealingly engage the drain rim; the central portion having a flexible leaf unified at its proximal end with the perimeter rim portion and otherwise separated from remaining surfaces such that the leaf is cantilevered over the drain opening; and the cantilevered leaf having sufficient resilience in its connection to the perimeter rim such that it collapses into the drain opening with the weight of water droplets on its upper surface and returns to a closed position upon the discharge of the droplets into the drain opening.
 2. The drain valve of claim 1 wherein: the central portion is bisected by a brace portion unified at both ends with the perimeter rim and having a cantilevered leaf on either side of the brace.
 3. The drain valve of claim 2 wherein: said drain valve is installable on a wastewater drain having a threaded drain strainer bolt mated to a threaded crosshair in the drainpipe; and the brace has hole at its center point such that the hole can accept the through passage of the drain strainer bolt to align the drain valve on center with the drain opening.
 4. The drain valve of claim 2 wherein: the valve is a unified construction.
 5. The drain valve of claim 3 wherein: the valve is composed of a polymeric material.
 6. The drain valve of claim 1 wherein: a gap at the perimeter of the cantilevered leaf prevents the leaf from snagging on burrs produced during manufacture and particulate matter such as soapscum adhering to the leaf and opposing edges during drainage.
 7. The drain valve of claim 6 wherein: the gap at the perimeter of the leaf has rounded endpoints and rounded vertices such that debris is incapable of being wedged into an acute corner or snagged on an acute point.
 8. The drain valve of claim 7 wherein: the central portion is bisected by a brace portion unified at both ends with the perimeter rim and having a cantilevered leaf on either side of the brace.
 9. The drain valve of claim 8 wherein: said drain valve is installable on a wastewater drain having a threaded drain strainer bolt mated to a threaded crosshair in the drainpipe; and the brace has hole at its center point such that the hole can accept the through passage of the drain strainer bolt to align the drain valve on center with the drain opening.
 10. The drain valve of claim 8 wherein: the valve is a unified construction.
 11. The drain valve of claim 9 wherein: the valve is composed of a polymeric material.
 12. A drain valve installable on a wastewater drain having a vertical drain pipe and a drain opening with an adjacent drain rim, the drain valve comprising: a drain strainer portion installable over the drain opening having a plurality of small apertures and a concave underside with a perimeter edge larger than the drain opening; a substantially flexible disc having a perimeter rim portion affixed to the underside of the drain strainer within the perimeter edge and a central portion aligned over the drain opening; the central portion having a flexible leaf unified at its proximal end with the perimeter rim portion and otherwise separated from remaining surfaces such that the leaf is cantilevered over the drain opening; and the cantilevered leaf having sufficient resilience in its proximal connection to the perimeter rim such that it collapses into the drain opening with the weight of water droplets on its upper surface and returns to a closed position upon the discharge of the droplets into the drain opening.
 13. The drain valve of claim 12 wherein: a gap at the perimeter of the cantilevered leaf prevents the leaf from snagging on burrs produced during manufacture and particulate matter such as soapscum adhering to the leaf and opposing edges during drainage.
 14. The drain valve of claim 13 wherein: the gap at the perimeter of the leaf has rounded endpoints and rounded vertices such that debris is incapable of being wedged into an acute corner or snagged on an acute point.
 15. The drain valve of claim 14 wherein: the central portion is bisected by a brace portion unified at both ends with the perimeter rim and having a cantilevered leaf on either side of the brace.
 16. The drain valve of claim 15 wherein: said drain valve is installable on a wastewater drain having a threaded drain strainer bolt mated to a threaded crosshair in the drainpipe; and the brace has hole at its center point such that the hole can accept the through passage of the drain strainer bolt to align the drain valve on center with the drain opening.
 17. A drain valve for installation in a wastewater drain having a vertical drain pipe and a drain opening, the drain valve comprising: a cup installable inside the drain opening having a cylindrical wall substantially sealing the inside wall of the drainpipe and a floor; the cup floor comprised of a substantially flexible disc having a perimeter rim and a central portion; the central portion having a flexible leaf unified at its proximal end with the perimeter rim portion and otherwise separated from remaining surfaces such that the leaf is cantilevered over the drain pipe; and the cantilevered leaf having sufficient resilience in its proximal connection to the perimeter rim such that it collapses into the drain pipe with the weight of water droplets on its upper surface and returns to a closed position upon the discharge of the droplets into the drain pipe.
 18. The drain valve of claim 17 wherein: a gap at the perimeter of the cantilevered leaf prevents the leaf from snagging on burrs produced during manufacture and particulate matter such as soapscum adhering to the leaf and opposing edges during drainage.
 19. The drain valve of claim 18 wherein: the gap at the perimeter of the leaf has rounded endpoints and rounded vertices such that debris is incapable of being wedged into an acute corner or snagged on an acute point.
 20. The drain valve of claim 19 wherein: the central portion of the cup floor is bisected by a brace portion unified at both ends with the perimeter rim and having a cantilevered leaf on either side of the brace. 